A mobile communication system includes a User Equipment (UE), a base station, and a radio network control device. For ease of description, it is assumed that the base station is a NodeB of Universal Mobile Telecommunications System, and that the radio network control device is a Radio Network Controller (RNC) hereunder. The channel between the UE and the NodeB and the channel between the NodeB and the RNC are Random Access Channels (RACHs).
To enhance the data transmission rate between the UE and the NodeB, a solution is put forward in the industry: using High Speed Downlink Packet Access (HSDPA) in the downlink common channel, thus making the theoretical downlink transmission rate as high as 100 Kbps. However, the downlink transmission rate is affected by the uplink transmission rate. For example, uplink transmission is currently performed on a shared RACH, which leads to slow uplink response and affects the downlink transmission rate.
To solve the problem, another solution is put forward in the industry: using High Speed Uplink Packet Access (HSUPA) to implement random access. This solution requires the UE to use an Enhanced Dedicated Channel (E-DCH) transmission channel to transmit the specific messages in the uplink transmission at random access. That is, an E-DCH should be used between the UE and the NodeB. This solution increases the speed of exchanging information between the UE and the NodeB massively.
During implementing of the present invention, the inventor finds at least the following problems in the prior art.
To increase the speed of transmitting the data sent by the UE in the uplink direction between the RNC and the NodeB, an E-DCH transmission channel may also be used between the RNC and the NodeB. Because the UE data quantity is small and intermittent, if a dedicated E-DCH channel is used between the RNC and the NodeB, resources are wasted drastically.
The channel between the RNC and the NodeB is port-based. This channel is different from the air interface based channel between the UE and the NodeB, and the method for allocating an E-DCH transmission channel between the UE and the NodeB at random access is not applicable to allocation of the channel between the RNC and the NodeB.